Synthesis of potassium-zinc hexacyanoferrate and their SPEEK composite cation exchange membranes for selective recovery of cesium from aqueous system

Abstract

Potassium-Zinc hexacyanoferrate adsorbent was prepared by precipitation method and further its composite membrane has been fabricated using sulphonated poly (ether ether ketone) (SPEEK) to investigate cesium (Cs+) recovery from aqueous media. The formation of desired adsorbent material was confirmed by Powder X-ray diffraction (PXRD) while chemical structure was assessed by Fourier-transform infrared spectroscopy (FT-IR). The BET surface area, pore volume and pore diameter found as 298.6 m2/g, 0.1034 cm3/g and 3.04 nm respectively calculated by Brunauer and Emmett and Teller (BET) surface area analyzer. The adsorbent synthesized was observed to work efficiently with maximum adsorption capacity of 54.64 mg Cs/g of adsorbent for Langmuir isotherm model. There was no effect of competing ion (Na+, K+, Mg2+, Ca2+) on adsorption performance during Cs+ removal. Cs+ recovery from the aqueous system in presence of 1000 ppm NaCl was performed using SPEEK composite membrane by electrodialysis. Observing the electrodialysis performance, composite membrane exhibited a high removal/recovery for Cs+ ions than Na+, K+, Mg2+ and Ca2+. The composite membrane exhibited a remarkable removal efficiency for Cs+ ion, which is 33.85 times larger than pristine SPEEK membrane. These results confirm composite membrane as promising candidate for the selective recovery/removal of cesium ions from aqueous solution in existence of intrusive ions and can effectively be applicable for industrial applications.